mcp-csharp-test

name	mcp-csharp-test
description	Use when testing a C# MCP server's tools, stateless HTTP endpoint, MRTR retries, tasks, Apps metadata, or conformance behavior.
license	MIT
version	0.2.0

C# MCP Server Testing

Derived from dotnet/skills under MIT; updated for ModelContextProtocol 2.0.0 and MCP 2026-07-28. See ../../THIRD-PARTY-NOTICES.md.

Test observable contracts at three levels:

1. Unit-test tool logic with real validation boundaries and deterministic dependencies.
2. Test stdio or WebApplicationFactory integration through the SDK client; verify listing and invocation, not private registration details.
3. Start the real stateless HTTP endpoint; test its 2026 contract directly. Use $mcp-conformance only for its supported 2025/draft wire coverage.

Modern HTTP cases

• Every HTTP request supplies request _meta and a matching Mcp-Method; every POST supplies matching MCP-Protocol-Version. Test that missing capability fails the relevant request, not a later session call.
• Assert an MCP-Protocol-Version/body or Mcp-Method/body mismatch returns -32020.
• Assert a required capability failure returns -32021; unsupported revision returns -32022.
• Assert legacy initialize, session GET/DELETE, and accidental Mcp-Session-Id behavior are rejected or intentionally routed according to the endpoint policy.

MRTR and Tasks

For MRTR, invoke a tool that returns/throws InputRequiredResult/InputRequiredException, then reissue the original request with a new JSON-RPC ID and inputResponses. Verify sealed requestState is rejected if altered. For Tasks, reference ModelContextProtocol.Extensions.Tasks, configure an IMcpTaskStore with WithTasks(store), create a task, and observe its explicit lifecycle update; do not test it as a tool retry.

Apps and AOT

Verify that an Apps-enabled tool advertises the intended ui:// resource metadata and visibility. Build the AOT configuration to prove explicit WithTools<T>() registration replaces assembly scanning.

Commands

dotnet test
dotnet publish -p:PublishAot=true

Use focused tests while iterating; run the complete affected suite before delivery. $mcp-conformance owns supported legacy/draft wire coverage, while this skill owns modern and application semantics.